Who’s behind this company’s share price drop?

Daniel Roland | AFP | Getty Images

Iceberg Research, the anonymous commenter that caused shares in Singapore-listed Noble Group to tumble this week, may soon find itself unmasked.

Iceberg released a report, dated Sunday, headlined "Noble Group, a repeat of Enron," alleging that the Singapore-listed commodities trader's accounting treatments were "unusual," result in "fabricated" profit and "intentionally misleads credit agencies and investors." The report, together with the promise of more to come, sent the shares down nearly 13 percent on Monday and Tuesday despite Noble's strongly worded denials.

Now Singapore's market watchdogs are on the case.

Read More Noble shares take second-day drubbing

"The Monetary Authority of Singapore (MAS) is reviewing the statements in the Iceberg research report," Singapore's central bank said in an emailed statement Wednesday. "MAS will take appropriate action if there are breaches of the Securities & Futures Act."

Noble said it welcomed the MAS investigation.

Iceberg Research, however, brushed aside the news of the regulator's scrutiny.

"It is perfectly normal that the regulators review our report. As many people have remarked, we use public financial information, which should simplify the review process," it said in an emailed response to a request for comment. Iceberg's emailed communications have repeatedly shifted between using "I" and "we."

Noble's stock price fell a cumulative 12.9 percent on Monday and Tuesday, but recovered to close Wednesday up 1.9 percent.

In separate statements to the Singapore Stock Exchange Monday and Tuesday, Noble said it "completely rejected" the allegations, adding that all the information cited in the report was in the public domain and that the company has "a solid balance sheet and industry leading liquidity headroom."

Read More Are short sellers gunning for Singapore again?

The stock moves have been sharp considering there are few clues about who is behind Iceberg.

Speculation about who might be behind Iceberg has been rife this week. Its website is a blog with no archived reports and an "about" section that claims only that Iceberg identifies earnings misrepresentations. Its Twitter account has sent only a handful of tweets.

The anonymity may not last long. To obtain a domain name via the site, Iceberg needed to provide a physical address as well as either credit card or Paypal transaction details, a representative for said via email. also collects IP addresses, it said.

While's legal guidelines indicate it won't reveal the information without a subpoena or court order, regulators, or even Noble, could take that approach.

But it isn't clear whether Iceberg has much to fear from the Securities & Futures Act.

If Iceberg isn't trading in shares of Noble, as it claims in its report, its statements may not be a criminal issue, one lawyer told CNBC, adding that MAS regulations don't appear to be aimed at people who aren't actually dealing in the securities in some form.

Even if Iceberg's report is found to be inaccurate, the portion of the securities act prohibiting disseminating false or misleading information to induce securities transactions also considers whether the person "does not care whether the statement or information is true or false" or whether the statements were "reckless."

—By CNBC.Com's Leslie Shaffer; Follow her on Twitter @LeslieShaffer1